U.S. patent number 9,157,031 [Application Number 13/539,242] was granted by the patent office on 2015-10-13 for solvolysis of biomass to produce aqueous and organic products.
This patent grant is currently assigned to Virent, Inc.. The grantee listed for this patent is Sean Connolly, Randy Cortright, Paul Myren, Ming Qiao, Elizabeth Woods. Invention is credited to Sean Connolly, Randy Cortright, Paul Myren, Ming Qiao, Elizabeth Woods.
United States Patent |
9,157,031 |
Qiao , et al. |
October 13, 2015 |
Solvolysis of biomass to produce aqueous and organic products
Abstract
The present invention provides processes for deconstructing
biomass to produce aqueous and organic products using a solvent
produced in a bioreforming reaction.
Inventors: |
Qiao; Ming (Pewaukee, WI),
Woods; Elizabeth (Middleton, WI), Myren; Paul (Madison,
WI), Cortright; Randy (Madison, WI), Connolly; Sean
(Madison, WI) |
Applicant: |
Name |
City |
State |
Country |
Type |
Qiao; Ming
Woods; Elizabeth
Myren; Paul
Cortright; Randy
Connolly; Sean |
Pewaukee
Middleton
Madison
Madison
Madison |
WI
WI
WI
WI
WI |
US
US
US
US
US |
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Assignee: |
Virent, Inc. (Madison,
WI)
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Family
ID: |
47352685 |
Appl.
No.: |
13/539,242 |
Filed: |
June 29, 2012 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20120318258 A1 |
Dec 20, 2012 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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13339720 |
Dec 29, 2011 |
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13339994 |
Dec 29, 2011 |
8642813 |
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13539242 |
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13479004 |
May 23, 2012 |
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61428472 |
Dec 30, 2010 |
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61481551 |
May 2, 2011 |
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61428461 |
Dec 30, 2010 |
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61489135 |
May 23, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10G
1/06 (20130101); C10G 3/45 (20130101); C07D
311/72 (20130101); C13K 13/002 (20130101); C13K
13/00 (20130101); C10G 1/065 (20130101); C08B
30/00 (20130101); C13K 1/02 (20130101); C13K
11/00 (20130101); C08H 6/00 (20130101); C13B
10/14 (20130101); C10G 3/00 (20130101); C08B
30/12 (20130101); C08H 8/00 (20130101); C07J
75/00 (20130101); C11B 3/006 (20130101); C10G
3/47 (20130101); C10G 3/49 (20130101); D21B
1/021 (20130101); C10G 2300/44 (20130101); Y02P
30/20 (20151101); C10G 2300/42 (20130101); C10G
2400/30 (20130101); C10G 2400/22 (20130101); C10G
2300/1014 (20130101); C10G 2300/805 (20130101); C10G
2300/1011 (20130101) |
Current International
Class: |
C08B
37/00 (20060101); C10G 1/06 (20060101); C10G
3/00 (20060101); C13K 13/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2075347 |
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Jul 2009 |
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EP |
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1165141 |
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Sep 1969 |
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GB |
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2008109877 |
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Sep 2008 |
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WO |
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Other References
Fukuoka, et al., Catalytic Conversion of Cellulose into Sugar
Alcohols, Angew. Chem., 2006, 118:5285-5287. cited by applicant
.
Kobayashi, et al., Water-Tolerant Mesoporous-Carbon-Supported
Ruthenium Catalysts for the Hydrolysis of Cellulose to Glucose,
ChemSusChem, 2010, 3:440-443. cited by applicant.
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Primary Examiner: Mayes; Melvin C
Assistant Examiner: Cohen; Stefanie
Attorney, Agent or Firm: Quarles & Brady LLP
Government Interests
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with government support under award
#70NANB7H7023, requisition #4700558 awarded by NIST through the ATP
program. The government has certain rights in the invention.
Parent Case Text
RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser.
No. 13/339,720 filed Dec. 29, 2011, which claimed the benefit of
U.S. provisional Application No. 61/428,472 filed Dec. 30, 2010; is
a continuation-in-part of U.S. application Ser. No. 13/339,994, now
U.S. Pat. No. 8,642,813, filed Dec. 29, 2011, which claimed the
benefit of U.S. provisional Application No. 61/481,551 filed May 2,
2011 and U.S. provisional Application No. U.S. Provisional
61/428,461 filed Dec. 30, 2010; and is a continuation-in-part of
U.S. application Ser. No. 13/479,004 filed May 23, 2012, which
claimed the benefit of U.S. provisional Application No. 61/489,135
filed May 23, 2011. Each of these applications is incorporated
herein by reference in its entirety.
Claims
The invention claimed is:
1. A method of deconstructing biomass to produce a reaction
product, the method comprising: A. catalytically reacting water and
a water-soluble C.sub.2+O.sub.1+ oxygenated hydrocarbon in a liquid
or vapor phase with H.sub.2 in the presence of a deoxygenation
catalyst at a deoxygenation temperature and a deoxygenation
pressure to produce a biomass processing solvent comprising a
C.sub.2+O.sub.1-3 hydrocarbon in a reaction stream; and B. reacting
the biomass processing solvent with a biomass component at a
deconstruction temperature and a deconstruction pressure to produce
a reaction product, the reaction product comprising a biomass
hydrolysate, an organic phase, and a solid phase, wherein the
biomass hydrolysate comprises at least one member selected from the
group consisting of a water-soluble lignocellulose derivative, a
water-soluble cellulose derivative, a water-soluble hemicellulose
derivative, a water-soluble lignin derivative, a carbohydrate, a
starch, a monosaccharide, a disaccharide, a polysaccharide, a
sugar, a sugar alcohol, an alditol, a polyol, and a phenol.
2. The method of claim 1 wherein the organic phase comprises a
member selected from the group consisting of 4-ethyl phenol,
4-ethyl-2-methoxy phenol, 2-methoxy-4-propyl phenol, vanillin,
4-propyl syringol, vitamin E, steroids, long chain hydrocarbons,
long chain fatty acids, stilbenoids, flavonoids, terpenoids,
phenolics, aliphatics, lignans, alkanes, proteinaceous materials,
and a combination of two or more of the foregoing.
3. The method of claim 2 wherein the solid phase comprises a
residual biomass component and the deoxygenation catalyst.
4. The method of claim 3 further comprising: C. separating the
solid phase from the reaction product; D. separating the
deoxygenation catalyst from the solid phase; and E. regenerating
the deoxygenation catalyst.
5. The method of claim 1 wherein the deoxygenation catalyst
comprises a support and a member adhered to the support wherein,
the member is selected from the group consisting of Re, Cu, Fe, Ru,
Ir, Co, Rh, Pt, Pd, Ni, W, Os, Mo, Ag, Au, an alloy thereof, and a
combination of two or more of the foregoing.
6. A method of making a reaction product, the method comprising: A.
catalytically reacting water and a water-soluble oxygenated
hydrocarbon comprising a C.sub.2+O.sub.1+ hydrocarbon in an aqueous
liquid phase or a vapor phase with H.sub.2 in the presence of a
deoxygenation catalyst at a deoxygenation temperature and
deoxygenation pressure to produce an oxygenate comprising a
C.sub.2+O.sub.1-3 hydrocarbon in a reaction stream; B.
catalytically reacting in the liquid or vapor phase the oxygenate
in the presence of a condensation catalyst at a condensation
temperature and condensation pressure to produce a biomass
processing solvent comprising one or more C.sub.4+ compounds; C.
reacting the biomass processing solvent with a biomass component at
a deconstruction temperature and a deconstruction pressure to
produce a reaction product, the reaction product comprising a
biomass hydrolysate, an organic phase, and a solid phase, wherein
the biomass hydrolysate comprises at least one member selected from
the group consisting of a water-soluble lignocellulose derivative,
a water-soluble cellulose derivative, a water-soluble hemicellulose
derivative, a water-soluble lignin derivative, a carbohydrate, a
starch, a monosaccharide, a disaccharide, a polysaccharide, a
sugar, a sugar alcohol, an alditol, a polyol, and a phenol.
7. The method of claim 6 wherein the biomass processing solvent
comprises a member selected from the group consisting of an alkane,
an alkene and an aromatic.
8. The method of claim 7 wherein the biomass processing solvent
comprises a member selected from the group consisting of benzene,
toluene and xylene.
9. The method of claim 6 wherein the organic phase comprises a
member selected from the group consisting of 4-ethyl phenol,
4-ethyl-2-methoxy phenol, 2-methoxy-4-propyl phenol, vanillin,
4-propyl syringol, vitamin E, steroids, long chain hydrocarbons,
long chain fatty acids, stilbenoids, flavonoids, terpenoids,
phenolics, aliphatics, lignans, alkanes, proteinaceous materials,
and a mixture thereof.
10. The method of claim 9 further comprising: D. separating the
solid phase from the reaction product, wherein the solid phase
comprises a residual biomass component and the deoxygenation
catalyst E. separating the deoxygenation catalyst from the solid
phase; and F. regenerating the deoxygenation catalyst.
11. The method of claim 6 wherein the deoxygenation catalyst
comprises a support and a member adhered to the support wherein,
the member is selected from the group consisting of Re, Cu, Fe, Ru,
Ir, Co, Rh, Pt, Pd, Ni, W, Os, Mo, Ag, Au, an alloy thereof, and a
combination thereof.
12. A method of deconstructing biomass, the method comprising
reacting a biomass slurry with a biomass processing solvent
comprising a C.sub.2+O.sub.1-3 hydrocarbon at a deconstruction
temperature between about 80.degree. C. and 350.degree. C. and a
deconstruction pressure between about 100 psi and 2000 psi to
produce a reaction product comprising a biomass hydrolysate, an
organic phase, and a solid phase, the biomass hydrolysate
comprising at least one member selected from the group consisting
of a water-soluble lignocellulose derivative, water-soluble
cellulose derivative, water-soluble hemicellulose derivative,
water-soluble lignin derivative, carbohydrate, starch,
monosaccharide, disaccharide, polysaccharide, sugar, sugar alcohol,
alditol, polyol, and phenol, wherein the biomass processing solvent
is produced by catalytically reacting in the liquid or vapor phase
an aqueous feedstock solution comprising water and a water-soluble
oxygenated hydrocarbons comprising a C.sub.2+O.sub.1+ hydrocarbon
with H.sub.2 in the presence of a deoxygenation catalyst at a
deoxygenation temperature and deoxygenation pressure.
13. The method of claim 12 wherein the organic phase comprises a
member selected from the group consisting of 4-ethyl phenol,
4-ethyl-2-methoxy phenol, 2-methoxy-4-propyl phenol, vanillin,
4-propyl syringol, vitamin E, steroids, long chain hydrocarbons,
long chain fatty acids, stilbenoids, flavonoids, terpenoids,
phenolics, aliphatics, lignans, alkanes, proteinaceous materials,
and a mixture thereof.
14. The method of claim 12 further comprising separating the solid
phase from the reaction product, wherein the solid phase comprises
a residual biomass component and the deoxygenation catalyst.
15. The method of claim 14 further comprising separating the
deoxygenation catalyst from the solid phase.
16. The method of claim 15 further comprising regenerating the
deoxygenation catalyst.
17. The method of claim 12 wherein the deoxygenation temperature is
between about 80.degree. C. and 350.degree. C. and the
deoxygenation pressure is between about 100 and 2000 psi.
18. The method of claim 12 wherein the deoxygenation catalyst
comprises a support and a member adhered to the support wherein,
the member is selected from the group consisting of Re, Cu, Fe, Ru,
Ir, Co, Rh, Pt, Pd, Ni, W, Os, Mo, Ag, Au, an alloy thereof, and a
combination thereof.
19. The method of claim 18 wherein the support comprises a member
selected from group consisting of a carbon, silica, alumina,
zirconia, titania, vanadia, heteropolyacid, kieselguhr,
hydroxyapatite, chromia, zeolite, and mixtures thereof.
20. The method of claim 19, wherein the support is selected from
the group consisting of tungstated zirconia, tungsten modified
zirconia, tungsten modified alpha-alumina, or tungsten modified
theta alumina.
21. The method of claim 12 wherein the H.sub.2 comprises at least
one of an in situ-generated H.sub.2, external H.sub.2, or recycled
H.sub.2.
22. The method of claim 12, wherein the oxygenated hydrocarbon
comprises a member selected from the group consisting of a
lignocellulose derivative, a cellulose derivative, a hemicellulose
derivative, a lignin derivative, a carbohydrate, a starch, a
monosaccharide, a disaccharide, a polysaccharide, a sugar, a sugar
alcohol, an alditol, a polyol, and a phenol.
23. The method of claim 12, wherein the biomass processing solvent
comprises a member selected from the group consisting of an
alcohol, ketone, aldehyde, cyclic ether, ester, furan, hydroxy
carboxylic acid, carboxylic acid, a phenol, and a mixture
thereof.
24. The method of claim 23, wherein the biomass processing solvent
comprises a member selected from the group consisting of methanol,
ethanol, n-propyl alcohol, isopropyl alcohol, butyl alcohol,
pentanol, hexanol, cyclopentanol, cyclohexanol,
2-methylcyclopentanol, a hydroxyketone, a cyclic ketone, acetone,
propanone, butanone, pentanone, hexanone, 2-methyl-cyclopentanone,
ethylene glycol, 1,3-propanediol, propylene glycol, butanediol,
pentanediol, hexanediol, methylglyoxal, butanedione, pentanedione,
diketohexane, a hydroxyaldehyde, acetaldehyde, propionaldehyde,
butyraldehyde, pentanal, hexanal, formic acid, acetic acid,
propionic acid, butanoic acid, pentanoic acid, hexanoic acid,
lactic acid, glycerol, furan, tetrahydrofuran, dihydrofuran,
2-furan methanol, 2-methyl-tetrahydrofuran,
2,5-dimethyl-tetrahydrofuran, 2-ethyl-tetrahydrofuran, 2-methyl
furan, 2,5-dimethyl furan, 2-ethyl furan, hydroxylmethylfurfural,
3-hydroxytetrahydrofuran, tetrahydro-3-furanol,
5-hydroxymethyl-2(5H)-furanone,
dihydro-5-(hydroxymethyl)-2(3H)-furanone, tetrahydro-2-furoic acid,
dihydro-5-(hydroxymethyl)-2(3H)-furanone, tetrahydrofurfuryl
alcohol, 1-(2-furyl)ethanol, and hydroxymethyltetrahydrofurfural,
phenol, 4-methyl-phenol, 2-methoxy-phenol, 4-ethyl-phenol,
4-ethyl-2-methoxy-phenol, 4-propyl-phenol,
4-ethyl-2-methoxy-phenol, 2,6-dimethoxy-phenol,
2-methoxy-4-propyl-phenol, 2-methoxy-3-(2-propenyl)-phenol,
2,6-dimethoxy-4-(2-propenyl)-phenol, isomers thereof, and
combinations thereof.
Description
TECHNICAL FIELD
The present invention is directed to a process in which liquids
produced in a bioreforming process are used in the
solvent-facilitated deconstruction of biomass.
BACKGROUND OF THE INVENTION
The increasing cost of fossil fuel and environmental concerns have
stimulated worldwide interest in developing alternatives to
petroleum-based fuels, chemicals, and other products. Biomass
materials are a possible renewable alternative.
Lignocellulosic biomass includes three major components. Cellulose,
a primary sugar source for bioconversion processes, includes high
molecular weight polymers formed of tightly linked glucose
monomers. Hemicellulose, a secondary sugar source, includes shorter
polymers formed of various sugars. Lignin includes phenylpropanoic
acid moieties polymerized in a complex three dimensional structure.
The resulting composition of lignocellulosic biomass is roughly
40-50% cellulose, 20-25% hemicellulose, and 25-35% lignin, by
weight percent.
No cost-effective process currently exists for efficiently
converting cellulose, hemicellulose, and lignin to components
better suited for producing fuels, chemicals, and other products.
This is generally because each of the lignin, cellulose and
hemicellulose components demand distinct processing conditions,
such as temperature, pressure, catalysts, reaction time, etc. in
order to effectively break apart its polymer structure.
One can use expensive organic solvents such as acetone, ethanol,
4-methyl-2-pentanone, and solvent mixtures, to fractionate
lignocellulosic biomass into cellulose, hemicellulose, and lignin
streams (Paszner 1984; Muurinen 2000; and Bozell 1998). Using this
process, the organic solvents dissolve some of the lignin such that
it is possible to separate the dissolved lignin from the solid
cellulose and hemicellulose. To the extent that the lignin can be
separated, it can be burned for energy or can be converted with a
ZSM-5 catalyst to liquid fuel compounds, such as benzene, toluene,
and xylene (Thring 2000).
After removing the lignin from biomass, one can depolymerize the
delignified lignocellulose by acid catalytic hydrolysis using acids
such as sulfuric acid, phosphoric acid, and organic acids. Acid
catalytic hydrolysis produces a hydrolysate product containing
sugars, acid, and other components such as polyols,
oligosaccharides, organic acids, lignin, and proteins. The
hydrolysates can be separated using known fractionation processes.
One can alternatively employ a specialized acid catalytic
hydrolysis technology developed by Arkenol, Inc. to convert
cellulose and hemicellulose in biomass to sugars using highly
concentrated acid and to separate sugars from acid using a
simulated moving bed process (Farone 1996).
Cellulose and hemicellulose can be used as feedstock for various
bioreforming processes, including aqueous phase reforming (APR) and
hydrodeoxygenation (HDO)--catalytic reforming processes that, when
integrated with hydrogenation, can convert cellulose and
hemicellulose into hydrogen and hydrocarbons, including liquid
fuels and other chemical products. APR and HDO methods and
techniques are described in U.S. Pat. Nos. 6,699,457; 6,964,757;
6,964,758; and 7,618,612 (all to Cortright et al., and entitled
"Low-Temperature Hydrogen Production from Oxygenated
Hydrocarbons"); U.S. Pat. No. 6,953,873 (to Cortright et al., and
entitled "Low-Temperature Hydrocarbon Production from Oxygenated
Hydrocarbons"); U.S. Pat. Nos. 7,767,867 and 7,989,664 and U.S.
Application Ser. No. 2011/0306804 (all to Cortright, and entitled
"Methods and Systems for Generating Polyols"). Various APR and HDO
methods and techniques are described in U.S. Patent Application
Ser. Nos. 2008/0216391; 2008/0300434; and 2008/0300435 (all to
Cortright and Blommel, and entitled "Synthesis of Liquid Fuels and
Chemicals from Oxygenated Hydrocarbons"); U.S. Patent Application
Ser. No. 2009/0211942 (to Cortright, and entitled "Catalysts and
Methods for Reforming Oxygenated Compounds"); U.S. Patent
Application Ser. No. 2010/0076233 (to Cortright et al., and
entitled "Synthesis of Liquid Fuels from Biomass"); International
Patent Application No. PCT/US2008/056330 (to Cortright and Blommel,
and entitled "Synthesis of Liquid Fuels and Chemicals from
Oxygenated Hydrocarbons"); and commonly owned co-pending
International Patent Application No. PCT/US2006/048030 (to
Cortright et al., and entitled "Catalyst and Methods for Reforming
Oxygenated Compounds"), all of which are incorporated herein by
reference.
Biomass must be deconstructed to less complex oxygenated compounds
prior to use as feedstock for bioreforming processes. There remains
a need for cost-effective methods for separating biomass into
streams suitable for use in APR, HDO and other bioreforming
processes.
SUMMARY
The invention provides methods for making a biomass hydrolysate.
The method generally involves: (1) catalytically reacting water and
a water-soluble C.sub.2+O.sub.1+ oxygenated hydrocarbon in a liquid
or vapor phase with H.sub.2 in the presence of a deoxygenation
catalyst at a deoxygenation temperature and deoxygenation pressure
to produce a biomass processing solvent comprising a
C.sub.2+O.sub.1-3 hydrocarbon in a reaction stream; and (2)
reacting the biomass processing solvent with a biomass component at
a deconstruction temperature and a deconstruction pressure to
produce a biomass hydrolysate comprising at least one member
selected from the group consisting of a water-soluble
lignocellulose derivative, a water-soluble cellulose derivative, a
water-soluble hemicellulose derivative, a water-soluble lignin
derivative, a carbohydrate, a starch, a monosaccharide, a
disaccharide, a polysaccharide, a sugar, a sugar alcohol, an
alditol and a polyol.
One aspect of the invention is the composition of the biomass
processing solvent. In one embodiment, the biomass processing
solvent includes a member selected from the group consisting of an
alcohol, ketone, aldehyde, cyclic ether, ester diol, triol, hydroxy
carboxylic acid, carboxylic acid, and a mixture thereof.
The invention also provides a method of making a biomass
hydrolysate comprising the steps of: (1) providing water and a
water-soluble oxygenated hydrocarbon comprising a C.sub.2+O.sub.1+
hydrocarbon in an aqueous liquid phase or a vapor phase; (2)
providing H.sub.2; (3) catalytically reacting in the liquid or
vapor phase the oxygenated hydrocarbon with the H.sub.2 in the
presence of a deoxygenation catalyst at a deoxygenation temperature
and deoxygenation pressure to produce an oxygenate comprising a
C.sub.2+O.sub.1-3 hydrocarbon in a reaction stream; (4)
catalytically reacting in the liquid or vapor phase the oxygenate
in the presence of a condensation catalyst at a condensation
temperature and condensation pressure to produce a biomass
processing solvent comprising one or more C.sub.4+ compounds; and
(5) reacting the biomass processing solvent with a biomass
component at a deconstruction temperature and a deconstruction
pressure to produce a biomass hydrolysate comprising at least one
member selected from the group consisting of a water-soluble
lignocellulose derivative, a water-soluble cellulose derivative, a
water-soluble hemicellulose derivative, a water-soluble lignin
derivative, a carbohydrate, a starch, a monosaccharide, a
disaccharide, a polysaccharide, a sugar, a sugar alcohol, an
alditol, and a polyol.
The biomass processing solvent may include a member selected from
the group consisting of an alkane, alkene and an aromatic. In one
embodiment, the member is selected from the group consisting of
benzene, toluene and xylene.
The condensation catalyst may comprise a support and a member
adhered to the support selected from the group consisting of a
carbide, a nitride, zirconia, alumina, silica, an aluminosilicate,
a phosphate, a zeolite, a titanium oxide, a zinc oxide, a vanadium
oxide, a lanthanum oxide, a yttrium oxide, a scandium oxide, a
magnesium oxide, a cerium oxide, a barium oxide, a calcium oxide, a
hydroxide, a heteropolyacid, an inorganic acid, an acid modified
resin, a base modified resin, and combinations thereof.
The invention also provides a method of deconstructing biomass. The
method generally includes reacting a biomass slurry with a biomass
processing solvent comprising a C.sub.2+O.sub.1-3 hydrocarbon at a
deconstruction temperature between about 80.degree. C. and
350.degree. C. and a deconstruction pressure between about 100 psi
and 2000 psi to produce a biomass hydrolysate comprising at least
one member selected from the group consisting of a water-soluble
lignocellulose derivative, water-soluble cellulose derivative,
water-soluble hemicellulose derivative, water-soluble lignin
derivative, carbohydrate, starch, monosaccharide, disaccharide,
polysaccharide, sugar, sugar alcohol, alditol, and polyol, wherein
the biomass processing solvent is produced by catalytically
reacting in the liquid or vapor phase an aqueous feedstock solution
comprising water and a water-soluble oxygenated hydrocarbons
comprising a C.sub.2+O.sub.1+ hydrocarbon with H.sub.2 in the
presence of a deoxygenation catalyst at a deoxygenation temperature
and deoxygenation pressure.
The oxygenated hydrocarbon may include a member selected from the
group consisting of a lignocellulose derivative, a cellulose
derivative, a hemicellulose derivative, a carbohydrate, a starch, a
monosaccharide, a disaccharide, a polysaccharide, a sugar, a sugar
alcohol, an alditol, and a polyol.
Another aspect of the invention is that a portion of the biomass
hydrolysate produced by the process above is recycled and combined
with the biomass slurry.
The biomass processing solvent may comprise a member selected from
the group consisting of an alcohol, ketone, aldehyde, diol, triol,
cyclic ether, hydroxy carboxylic acid, carboxylic acid, and a
mixture thereof. In one embodiment, the biomass processing solvent
comprises a member selected from the group consisting of methanol,
ethanol, n-propyl alcohol, isopropyl alcohol, butyl alcohol,
pentanol, hexanol, cyclopentanol, cyclohexanol,
2-methylcyclopentanol, hydroxyketones, cyclic ketones, acetone,
propanone, butanone, pentanone, hexanone, 2-methyl-cyclopentanone,
ethylene glycol, 1,3-propanediol, propylene glycol, butanediol,
pentanediol, hexanediol, methylglyoxal, butanedione, pentanedione,
diketohexane, hydroxyaldehydes, acetaldehyde, propionaldehyde,
butyraldehyde, pentanal, hexanal, formic acid, acetic acid,
propionic acid, butanoic acid, pentanoic acid, hexanoic acid,
lactic acid, glycerol, furan, tetrahydrofuran, dihydrofuran,
2-furan methanol, 2-methyl-tetrahydrofuran,
2,5-dimethyl-tetrahydrofuran, 2-ethyl-tetrahydrofuran, 2-methyl
furan, 2,5-dimethyl furan, 2-ethyl furan, hydroxylmethylfurfural,
3-hydroxytetrahydrofuran, tetrahydro-3-furanol,
5-hydroxymethyl-2(5H)-furanone,
dihydro-5-(hydroxymethyl)-2(3H)-furanone, tetrahydro-2-furoic acid,
dihydro-5-(hydroxymethyl)-2(3H)-furanone, tetrahydrofurfuryl
alcohol, 1-(2-furyl)ethanol, and hydroxymethyltetrahydrofurfural,
isomers thereof, and combinations thereof.
The deoxygenation catalyst is capable of deoxygenating water
soluble oxygenated hydrocarbons to produce the biomass processing
solvent. The deoxygenation catalyst comprises a support and a
member adhered to the support selected from the group consisting of
Re, Cu, Fe, Ru, Ir, Co, Rh, Pt, Pd, Ni, W, Os, Mo, Ag, Au, an alloy
thereof, and a combination thereof. It may further comprise a
member selected from the group consisting of Mn, Cr, Mo, W, V, Nb,
Ta, Ti, Zr, Y, La, Sc, Zn, Cd, Ag, Au, Sn, Ge, P, Al, Ga, In, Tl,
and a combination thereof. The deoxygenation catalyst may have an
active metal function and an acidic function. The support may be a
member selected from group consisting of carbon, silica, alumina,
zirconia, titania, tungsten, vanadia, heteropolyacid, kieselguhr,
hydroxyapatite, chromia, zeolites, and mixtures thereof. The
support may be a member selected from the group consisting of
tungstated zirconia, tungsten modified zirconia, tungsten modified
alpha-alumina, or tungsten modified theta alumina.
Another aspect of the invention is that the H.sub.2 may be in
situ-generated H.sub.2, external H.sub.2, or recycled H.sub.2. The
H.sub.2 may be generated in situ by catalytically reacting in a
liquid phase or vapor phase a portion of the water and the
oxygenated hydrocarbon in the presence of an aqueous phase
reforming catalyst at a reforming temperature and reforming
pressure.
In one embodiment, the aqueous phase reforming catalyst may
comprise a support and a member adhered to the support selected
from the group consisting of Fe, Ru, Os, Ir, Co, Rh, Pt, Pd, Ni, an
alloy thereof, and a combination thereof. The aqueous phase
reforming catalyst may further comprise a member selected from the
group consisting of Cu, B, Mn, Re, Cr, Mo, Bi, W, V, Nb, Ta, Ti,
Zr, Y, La, Sc, Zn, Cd, Ag, Au, Sn, Ge, P, Al, Ga, In, Tl, an alloy
thereof, and a combination thereof. In another embodiment, the
aqueous phase reforming catalyst and the deoxygenation catalyst are
combined into a single catalyst.
The aqueous phase reforming and deoxygenation reactions are
conducted at a temperature and pressure where the thermodynamics
are favorable. In one embodiment, the reforming temperature is in
the range of about 100.degree. C. to about 450.degree. C. or about
100.degree. C. to about 300.degree. C., and the reforming pressure
is a pressure where the water and the oxygenated hydrocarbon are
gaseous. In another embodiment, the reforming temperature is in the
range of about 80.degree. C. to 400.degree. C., and the reforming
pressure is a pressure where the water and the oxygenated
hydrocarbon are liquid.
The deoxygenation temperature may be greater than 120.degree. C.,
or 150.degree. C., or 180.degree. C., or 200.degree. C., and less
than 325.degree. C., or 300.degree. C., or 280.degree. C., or
260.degree. C., or 240.degree. C., or 220.degree. C. The
deoxygenation pressure may be greater than 200 psig, or 365 psig,
or 500 psig or 600 psig, and less than 2500 psig, or 2250 psig, or
2000 psig, or 1800 psig, or 1500 psig, or 1200 psig, or 1000 psig.
The deoxygenation temperature may also be in the range of about
120.degree. C. to 325.degree. C., and the deoxygenation pressure is
at least 0.1 atmosphere. In other embodiments, the deoxygenation
temperature is in the range of about 120.degree. C. to about
325.degree. C. or about 200.degree. C. to 280.degree. C., and the
deoxygenation pressure is between about 365 psig and about 2500
psig or about 600 psig and 1800 psig.
In one embodiment, the APR catalyst and the deoxygenation catalyst
are combined into a single catalyst. In this aspect, the reforming
temperature and deoxygenation temperature may be in the range of
about 100.degree. C. to 325.degree. C., or about 120.degree. C. to
300.degree. C., or about 200.degree. C. to 280.degree. C., and the
reforming pressure and deoxygenation pressure may be in the range
of about 200 psig to 1500 psig, or about 200 psig to 1200 psig, or
about 200 psig to 725 psig.
In another embodiment, the step of reacting a biomass slurry with a
biomass processing solvent is performed in the same reactor as the
step of catalytically reacting the aqueous feedstock solution with
H.sub.2 in the presence of a deoxygenation catalyst. The
deconstruction temperature and deoxygenation temperature may be in
the range of about 100.degree. C. to 325.degree. C., about
120.degree. C. to 300.degree. C., or about 200.degree. C. to
280.degree. C., and the deconstruction pressure and deoxygenation
pressure may be in the range of about 200 psig to 1500 psig, about
200 psig to 1200 psig, or about 600 psig to 1800 psig.
Another aspect of the invention includes the step of dewatering the
biomass hydrolysate.
The invention also provides a method for deconstructing biomass to
produce a reaction product comprising a biomass hydrolysate,
organic phase, and solid phase. The method generally includes: (1)
catalytically reacting water and a water-soluble C.sub.2+O.sub.1+
oxygenated hydrocarbon in a liquid or vapor phase with H.sub.2 in
the presence of a deoxygenation catalyst at a deoxygenation
temperature and deoxygenation pressure to produce a biomass
processing solvent comprising a C.sub.2+O.sub.1-3 hydrocarbon in a
reaction stream; and (2) reacting the biomass processing solvent
with a biomass component at a deconstruction temperature and a
deconstruction pressure to produce a reaction product comprising a
biomass hydrolysate, an organic phase, and a solid phase, the
biomass hydrolysate comprising at least one member selected from
the group consisting of a water-soluble lignocellulose derivative,
a water-soluble cellulose derivative, a water-soluble hemicellulose
derivative, a water-soluble lignin derivative, a carbohydrate, a
starch, a monosaccharide, a disaccharide, a polysaccharide, a
sugar, a sugar alcohol, an alditol a polyol, and a phenol.
In one embodiment the organic phase comprises a member selected
from the group consisting of 4-ethyl phenol, 4-ethyl-2-methoxy
phenol, 2-methoxy-4-propyl phenol, vanillin, 4-propyl syringol,
vitamin E, steroids, long chain hydrocarbons, long chain fatty
acids, stilbenoids, flavonoids, terpenoids, phenolics, aliphatics,
lignans, alkanes, proteinaceous material and a mixture thereof.
In one embodiment, the solid phase comprises a residual biomass
component and the deoxygenation catalyst.
The deconstruction method may also include: (3) separating the
solid phase from the reaction product; (4) separating the
deoxygenation catalyst from the solid phase; and (5) regenerating
the deoxygenation catalyst.
In one embodiment, the deoxygenation catalyst comprises a support
and a member adhered to the support wherein, the member is selected
from the group consisting of Re, Cu, Fe, Ru, Ir, Co, Rh, Pt, Pd,
Ni, W, Os, Mo, Ag, Au, an alloy thereof, and a combination
thereof.
The invention also provides a method of making a reaction product
comprising the steps of: (1) providing water and a water-soluble
oxygenated hydrocarbon comprising a C.sub.2+O.sub.1+ hydrocarbon in
an aqueous liquid phase or a vapor phase; (2) providing H.sub.2;
(3) catalytically reacting in the liquid or vapor phase the
oxygenated hydrocarbon with the H.sub.2 in the presence of a
deoxygenation catalyst at a deoxygenation temperature and
deoxygenation pressure to produce an oxygenate comprising a
C.sub.2+O.sub.1-3 hydrocarbon in a reaction stream; (4)
catalytically reacting in the liquid or vapor phase the oxygenate
in the presence of a condensation catalyst at a condensation
temperature and condensation pressure to produce a biomass
processing solvent comprising one or more C.sub.4+ compounds; (5)
reacting the biomass processing solvent with a biomass component at
a deconstruction temperature and a deconstruction pressure to
produce a reaction product comprising a biomass hydrolysate, an
organic phase, and a solid phase, the biomass hydrolysate
comprising at least one member selected from the group consisting
of a water-soluble lignocellulose derivative, a water-soluble
cellulose derivative, a water-soluble hemicellulose derivative, a
water-soluble lignin derivative, a carbohydrate, a starch, a
monosaccharide, a disaccharide, a polysaccharide, a sugar, a sugar
alcohol, an alditol, a polyol, and a phenol.
In one embodiment, the biomass processing solvent comprises a
member selected from the group consisting of an alkane, alkene and
an aromatic.
In another embodiment, the biomass processing solvent comprises a
member selected from the group consisting of benzene, toluene and
xylene.
The method for making a reaction product may also include: (6)
separating the solid phase from the reaction product, wherein the
solid phase comprises a residual biomass component and the
deoxygenation catalyst; (7) separating the deoxygenation catalyst
from the solid phase; and (8) regenerating the deoxygenation
catalyst.
The invention also provides a method of deconstructing biomass. The
method generally includes reacting a biomass slurry with a biomass
processing solvent comprising a C.sub.2+O.sub.1-3 hydrocarbon at a
deconstruction temperature between about 80.degree. C. and
350.degree. C. and a deconstruction pressure between about 100 psi
and 2000 psi to produce a reaction product comprising a biomass
hydrolysate, an organic phase, and a solid phase, the biomass
hydrolysate comprising at least one member selected from the group
consisting of a water-soluble lignocellulose derivative,
water-soluble cellulose derivative, water-soluble hemicellulose
derivative, water-soluble lignin derivative, carbohydrate, starch,
monosaccharide, disaccharide, polysaccharide, sugar, sugar alcohol,
alditol, polyol, and phenol, wherein the biomass processing solvent
is produced by catalytically reacting in the liquid or vapor phase
an aqueous feedstock solution comprising water and a water-soluble
oxygenated hydrocarbons comprising a C.sub.2+O.sub.1+ hydrocarbon
with H.sub.2 in the presence of a deoxygenation catalyst at a
deoxygenation temperature and deoxygenation pressure.
The deconstruction method may also include: separating the solid
phase from the reaction product, wherein the solid phase comprises
a residual biomass component and the deoxygenation catalyst;
separating the deoxygenation catalyst from the solid phase; and
regenerating the deoxygenation catalyst.
In one embodiment, the deoxygenation temperature may be between
about 80.degree. C. and 350.degree. C. and the deoxygenation
pressure is between about 100 and 2000 psi.
In another embodiment, the deoxygenation catalyst may comprise a
support and a member adhered to the support wherein, the member may
be selected from the group consisting of Re, Cu, Fe, Ru, Ir, Co,
Rh, Pt, Pd, Ni, W, Os, Mo, Ag, Au, an alloy thereof, and a
combination thereof. The support may comprise a member selected
from group consisting of a carbon, silica, alumina, zirconia,
titania, vanadia, heteropolyacid, kieselguhr, hydroxyapatite,
chromia, zeolite, and mixtures thereof. The support may also be
selected from the group consisting of tungstated zirconia, tungsten
modified zirconia, tungsten modified alpha-alumina, or tungsten
modified theta alumina.
In yet another embodiment, the biomass processing solvent comprises
a member selected from the group consisting of methanol, ethanol,
n-propyl alcohol, isopropyl alcohol, butyl alcohol, pentanol,
hexanol, cyclopentanol, cyclohexanol, 2-methylcyclopentanol, a
hydroxyketone, a cyclic ketone, acetone, propanone, butanone,
pentanone, hexanone, 2-methyl-cyclopentanone, ethylene glycol,
1,3-propanediol, propylene glycol, butanediol, pentanediol,
hexanediol, methylglyoxal, butanedione, pentanedione, diketohexane,
a hydroxyaldehyde, acetaldehyde, propionaldehyde, butyraldehyde,
pentanal, hexanal, formic acid, acetic acid, propionic acid,
butanoic acid, pentanoic acid, hexanoic acid, lactic acid,
glycerol, furan, tetrahydrofuran, dihydrofuran, 2-furan methanol,
2-methyl-tetrahydrofuran, 2,5-dimethyl-tetrahydrofuran,
2-ethyl-tetrahydrofuran, 2-methyl furan, 2,5-dimethyl furan,
2-ethyl furan, hydroxylmethylfurfural, 3-hydroxytetrahydrofuran,
tetrahydro-3-furanol, 5-hydroxymethyl-2(5H)-furanone,
dihydro-5-(hydroxymethyl)-2(3H)-furanone, tetrahydro-2-furoic acid,
dihydro-5-(hydroxymethyl)-2(3H)-furanone, tetrahydrofurfuryl
alcohol, 1-(2-furyl)ethanol, and hydroxymethyltetrahydrofurfural,
phenol, 4-methyl-phenol, 2-methoxy-phenol, 4-ethyl-phenol,
4-ethyl-2-methoxy-phenol, 4-propyl-phenol,
4-ethyl-2-methoxy-phenol, 2,6-dimethoxy-phenol,
2-methoxy-4-propyl-phenol, 2-methoxy-3-(2-propenyl)-phenol,
2,6-dimethoxy-4-(2-propenyl)-phenol, isomers thereof, and
combinations thereof.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram illustrating a process for converting
biomass to liquid fuels.
FIG. 2 is a flow diagram illustrating a process for converting
biomass to liquid fuels using a biomass processing solvent derived
from the conversion of biomass hydrolysate in an APR/HDO
process.
FIG. 3 illustrates the results of biomass deconstruction using
benzene, toluene, and 4-methyl-2-pentanone.
FIG. 4 illustrates the major compounds in an APR aqueous product
solvent.
FIG. 5 illustrates the composition of the aqueous phase product
according to the present invention.
FIG. 6 is an infrared (IR) chromatogram of the organic phase
according to the present invention.
FIG. 7 illustrates prevalent compounds found in the organic phase
identified using combined gas chromatography (GC) and mass
spectrometry (MS) according to the present invention.
FIG. 8 is a GC-IR of the organic phase according to the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides processes for hydrolyzing or
deconstructing biomass using a biomass processing solvent produced
in a bioreforming process. The resulting product stream includes a
biomass hydrolysate that can be further processed in a bioreforming
process to provide the biomass processing solvent and a product
stream for further conversion to desired compounds. The
bioreforming process and deconstruction process may occur
separately in different reactors or together in a single reactor,
and generally occur in steady-state as part of a continuous
process.
As used herein, the term "biomass" refers to, without limitation,
organic materials produced by plants (such as leaves, roots, seeds
and stalks), and microbial and animal metabolic wastes. Common
biomass sources include: (1) agricultural residues, including corn
stover, straw, seed hulls, sugarcane leavings, bagasse, nutshells,
cotton gin trash, and manure from cattle, poultry, and hogs; (2)
wood materials, including wood or bark, sawdust, timber slash, and
mill scrap; (3) municipal solid waste, including recycled paper,
waste paper and yard clippings; (4) energy crops, including
poplars, willows, switch grass, miscanthus, sorghum, alfalfa,
prairie bluestream, corn, soybean, and the like; and (5)
algae-derived biomass, including carbohydrates and lipids from
microalgae and macroalgae. The term also refers to the primary
building blocks of the above, namely, lignin, cellulose,
hemicellulose and carbohydrates, such as saccharides, sugars and
starches, among others.
As used herein, the term "bioreforming" refers to, without
limitation, processes for catalytically converting biomass and
other carbohydrates to lower molecular weight hydrocarbons and
oxygenated compounds, such as alcohols, ketones, cyclic ethers,
esters, carboxylic acids, aldehydes, diols and other polyols, using
aqueous phase reforming, hydrogenation, hydrogenolysis,
hydrodeoxygenation and/or other conversion processes involving the
use of heterogeneous catalysts. Bioreforming also includes the
further catalytic conversion of such lower molecular weight
oxygenated compounds to C.sub.4+ compounds.
The deconstruction process uses a biomass processing solvent or
solvent mixture produced in a bioreforming process. One such
process is illustrated in FIG. 1. First, in the deconstruction
process, a biomass slurry is combined with a biomass processing
solvent or solvent mixture produced in a bioreforming process. The
biomass slurry may include any type of biomass that has been
chopped, shredded, pressed, ground or processed to a size amenable
for conversion. The biomass processing solvent or solvent mixture
may contain a wide range of oxygenates, such as ketones, alcohols,
cyclic ethers, aldehydes, acids, esters, diols, and other polyols,
and/or C.sub.4+ hydrocarbons, such as C.sub.4+ alkanes, C.sub.4+
alkenes, and aromatic compounds, including benzene, toluene,
xylene. In a preferred embodiment, the biomass processing solvent
or solvent mixture is derived from the biomass hydrolysate or, as
illustrated in FIGS. 1 and 2, from the further processing of the
biomass hydrolysate in a bioreforming process.
The product stream resulting from the biomass deconstruction will
generally include water, unreacted or under-reacted product,
residual biomass, ash components, extractives, and a biomass
hydrolysate that includes lignin and lignocellulosic derivatives,
cellulose and cellulosic derivatives, hemicellulose and
hemicellulosic derivatives, carbohydrates, starches,
monosaccharides, disaccharides, polysaccharides, sugars, sugar
alcohols, alditols, polyols, phenols, and mixtures thereof. In
certain embodiments the biomass hydrolysate may contain sugars,
organic acids, oxygenated hydrocarbons derived from lignin,
cellulose, and hemicellulose, contaminants, mineral salts, mineral
acids, deconstruction solvents, extractives (e.g., terpenoids,
stilbenes, flavonoids, phenolics, aliphatics, lignans, alkanes, and
proteinaceous materials, etc.), ash components (e.g., Al, Ba, Ca,
Fe, K, Mg, Mn, P, S, Si, Zn, etc.), and other organic products
(e.g., 4-ethyl phenol, 4-ethyl-2-methoxy phenol, 2-methoxy-4-propyl
phenol, vanillin, 4-propyl syringol, vitamin E, steroids, long
chain hydrocarbons, long chain fatty acids, stilbenoids, etc.).
Preferably, the biomass hydrolysate includes sugar, sugar alcohols,
starch, saccharides and other polyhydric alcohols. More preferably,
the biomass hydrolysate includes a sugar, such as glucose,
fructose, sucrose, maltose, lactose, mannose or xylose, or a sugar
alcohol, such as arabitol, erythritol, glycerol, isomalt, lactitol,
malitol, mannitol, sorbitol, xylitol, arabitol, or glycol. In
certain embodiments, the biomass hydrolysate may also include
alcohols, ketones, cyclic ethers, esters, carboxylic acids,
aldehydes, diols, other polyols, and phenols that are useful as the
processing solvent. In other embodiments, the biomass hydrolysate
may also include mono-oxygenated hydrocarbons that may be further
converted to C.sub.4+ hydrocarbons, such as C.sub.4+ alkanes,
C.sub.4+ alkenes, and aromatic compounds, including benzene,
toluene, xylene, which are useful as liquid fuels and
chemicals.
The resulting biomass hydrolysate may be collected for further
processing in a bioreforming process or, alternatively, used as a
feedstock for other conversion processes, including the production
of fuels and chemicals using fermentation or enzymatic
technologies. For example, water-soluble carbohydrates, such as
starch, monosaccharides, disaccharides, polysaccharides, sugars,
and sugar alcohols, and water-soluble derivatives from the lignin,
hemicellulose and cellulose are suitable for use in bioreforming
processes. Alternatively, the resulting biomass hydrolysate may be
recycled and combined in the biomass slurry for further conversion
or use as a processing solvent.
In certain applications, the biomass product stream undergoes one
or more separation steps to separate the ash, unreacted biomass and
under-reacted biomass from the product stream to provide the
biomass hydrolysate. The biomass hydrolysate may also require
further processing to separate aqueous phase products from organic
phase products, such as lignin-based hydrocarbons not suitable for
bioreforming processes. The biomass hydrolysate may also be
dewatered or further purified prior to being introduced into the
bioreforming process. Such dewatering and purification processes
are known in the art and may include simulated moving bed
technology, distillation, filtration, etc.
Biomass Processing Solvent
Bioreforming processes convert starches, sugars and other polyols
to a wide range of oxygenates, including organic compounds that
facilitate biomass deconstruction. As used herein, "oxygenates"
generically refers to hydrocarbon compounds having 2 or more carbon
atoms and 1, 2 or 3 oxygen atoms (referred to herein as
C.sub.2+O.sub.1-3 hydrocarbons), such as alcohols, ketones,
aldehydes, hydroxy carboxylic acids, carboxylic acids, cyclic
ethers, esters, diols and triols. Preferably, the oxygenates have
from 2 to 6 carbon atoms, or 3 to 6 carbon atoms. Alcohols may
include, without limitation, primary, secondary, linear, branched
or cyclic C.sub.2+ alcohols, such as ethanol, n-propyl alcohol,
isopropyl alcohol, butyl alcohol, isobutyl alcohol, butanol,
pentanol, cyclopentanol, hexanol, cyclohexanol,
2-methyl-cyclopentanonol, heptanol, octanol, nonanol, decanol,
undecanol, dodecanol, and isomers thereof. The ketones may include,
without limitation, hydroxyketones, cyclic ketones, diketones,
acetone, propanone, 2-oxopropanal, butanone, butane-2,3-dione,
3-hydroxybutan-2-one, pentanone, cyclopentanone, pentane-2,3-dione,
pentane-2,4-dione, hexanone, cyclohexanone,
2-methyl-cyclopentanone, heptanone, octanone, nonanone, decanone,
undecanone, dodecanone, methylglyoxal, butanedione, pentanedione,
diketohexane, and isomers thereof. The aldehydes may include,
without limitation, hydroxyaldehydes, acetaldehyde,
propionaldehyde, butyraldehyde, pentanal, hexanal, heptanal,
octanal, nonal, decanal, undecanal, dodecanal, and isomers thereof.
The carboxylic acids may include, without limitation, formic acid,
acetic acid, propionic acid, butanoic acid, pentanoic acid,
hexanoic acid, heptanoic acid, isomers and derivatives thereof,
including hydroxylated derivatives, such as 2-hydroxybutanoic acid
and lactic acid. The diols may include, without limitation,
ethylene glycol, propylene glycol, 1,3-propanediol, butanediol,
pentanediol, hexanediol, heptanediol, octanediol, nonanediol,
decanediol, undecanediol, dodecanediol, lactones, and isomers
thereof. The triols may include, without limitation, glycerol,
1,1,1 tris(hydroxymethyl)-ethane (trimethylolethane),
trimethylolpropane, hexanetriol, and isomers thereof. Cyclic ethers
include, without limitation, furan, furfural, tetrahydrofuran,
dihydrofuran, 2-furan methanol, 2-methyl-tetrahydrofuran,
2,5-dimethyl-tetrahydrofuran, 2-methyl furan,
2-ethyl-tetrahydrofuran, 2-ethyl furan, hydroxylmethylfurfural,
3-hydroxytetrahydrofuran, tetrahydro-3-furanol, 2,5-dimethyl furan,
5-hydroxymethyl-2(5H)-furanone,
dihydro-5-(hydroxymethyl)-2(3H)-furanone, tetrahydro-2-furoic acid,
dihydro-5-(hydroxymethyl)-2(3H)-furanone, tetrahydrofurfuryl
alcohol, 1-(2-furyl)ethanol, hydroxymethyltetrahydrofurfural, and
isomers thereof.
The above oxygenates may originate from any source, but are
preferably derived from oxygenated hydrocarbons resulting from the
initial processing of the biomass in the biomass slurry. Oxygenated
hydrocarbons may be any water-soluble oxygenated hydrocarbon having
two or more carbon atoms and at least one oxygen atom (referred to
herein as C.sub.2+O.sub.1+ hydrocarbons). Preferably, the
oxygenated hydrocarbon has 2 to 12 carbon atoms
(C.sub.1-12O.sub.1-11 hydrocarbon), and more preferably 2 to 6
carbon atoms (C.sub.1-6O.sub.1-6 hydrocarbon), and 1, 2, 3, 4, 5, 6
or more oxygen atoms. The oxygenated hydrocarbon may also have an
oxygen-to-carbon ratio ranging from 0.5:1 to 1.5:1, including
ratios of 0.75:1.0, 1.0:1.0, 1.25:1.0, 1.5:1.0, and other ratios
between. In one example, the oxygenated hydrocarbon has an
oxygen-to-carbon ratio of 1:1. Nonlimiting examples of preferred
water-soluble oxygenated hydrocarbons include starches,
monosaccharides, disaccharides, polysaccharides, sugar, sugar
alcohols, alditols, ethanediol, ethanedione, acetic acid, propanol,
propanediol, propionic acid, glycerol, glyceraldehyde,
dihydroxyacetone, lactic acid, pyruvic acid, malonic acid,
butanediols, butanoic acid, aldotetroses, tautaric acid,
aldopentoses, aldohexoses, ketotetroses, ketopentoses, ketohexoses,
alditols, hemicelluloses, cellulosic derivatives, lignocellulosic
derivatives, starches, polyols and the like. Preferably, the
oxygenated hydrocarbon includes starches, sugar, sugar alcohols,
saccharides and other polyhydric alcohols. More preferably, the
oxygenated hydrocarbon is a sugar, such as glucose, fructose,
sucrose, maltose, lactose, mannose or xylose, or a sugar alcohol,
such as arabitol, erythritol, glycerol, isomalt, lactitol, malitol,
mannitol, sorbitol, xylitol, ribitol, or glycol.
Production of the Biomass Processing Solvent
As shown in Table 1 below, the bioreforming process produces a
complex organic mixture. The mixture of different organics provides
good candidate compounds for a high quality biomass deconstruction
solvent.
TABLE-US-00001 TABLE 1 Typical Products of a Bioreforming Process %
of Component Phase Aqueous Phase 2-Pentanone 13.75 Butanoic acid
13.61 2-Butanone 13.08 Furan, tetrahydro-2,5-dimethyl- 10.70
Acetone 8.43 Propionic Acid 8.15 Acetic acid 4.82 Pentanoic acid
4.68 2-Butanol, (.+/-.)- 3.77 2-Hexanone 3.75 3-Hexanone 3.57
(R)-(-)-2-Pentanol 1.82 Isopropyl Alcohol 1.73 Hexanoic acid 1.09
2-Butanone, 3-hydroxy- 1.05 Organic Phase 3-Hexanone 12.98
2-Hexanone 12.60 2-Pentanone 9.53 Water 6.64 Butanoic acid 6.19
2-Furanmethanol, tetrahydro- 5.68 Furan, tetrahydro-2,5-dimethyl-
5.29 3-Pentanone 4.93 Pentanoic acid 4.41 2-Butanone 4.35 2H-Pyran,
tetrahydro-2-methyl- 2.78 2-Hexanol 2.22 Hexanoic acid 2.10 Furan,
tetrahydro-2-methyl- 1.95 2(3H)-Furanone, 5-ethyldihydro- 1.71
2-Pentanol 1.71 3-Hexanol 1.62 Hexane 1.55 Pentane 1.52 Propionic
Acid 1.42
The oxygenates are prepared by reacting an aqueous feedstock
solution containing water and the water-soluble oxygenated
hydrocarbons with hydrogen over a catalytic material to produce the
desired oxygenates. The hydrogen may be generated in situ using
aqueous phase reforming (in situ-generated H.sub.2 or APR H.sub.2),
or a combination of APR H.sub.2, external H.sub.2 or recycled
H.sub.2, or just simply external H.sub.2 or recycled H.sub.2. The
term "external H.sub.2" refers to hydrogen that does not originate
from the feedstock solution, but is added to the reactor system
from an external source. The term "recycled H.sub.2" refers to
unconsumed hydrogen, which is collected and then recycled back into
the reactor system for further use. External H.sub.2 and recycled
H.sub.2 may also be referred to collectively or individually as
"supplemental H.sub.2." In general, supplemental H.sub.2 may be
added for purposes of supplementing the APR hydrogen or to increase
the reaction pressure within the system, or to increase the molar
ratio of hydrogen to carbon and/or oxygen in order to enhance the
production yield of certain reaction product types, such as ketones
and alcohols.
In processes utilizing APR H.sub.2, the oxygenates are prepared by
catalytically reacting a portion of the aqueous feedstock solution
containing water and the water-soluble oxygenated hydrocarbons in
the presence of an APR catalyst at a reforming temperature and
reforming pressure to produce the APR H.sub.2, and catalytically
reacting the APR H.sub.2 (and recycled H.sub.2 and/or external
H.sub.2) with a portion of the feedstock solution in the presence
of a deoxygenation catalyst at a deoxygenation temperature and
deoxygenation pressure to produce the desired oxygenates. In
systems utilizing recycled H.sub.2 or external H.sub.2 as a
hydrogen source, the oxygenates are simply prepared by
catalytically reacting the recycled H.sub.2 and/or external H.sub.2
with the feedstock solution in the presence of the deoxygenation
catalyst at the deoxygenation temperatures and pressures. In each
of the above, the oxygenates may also include recycled oxygenates
(recycled C.sub.2+O.sub.1-3 hydrocarbons).
The deoxygenation catalyst is preferably a heterogeneous catalyst
having one or more active materials capable of catalyzing a
reaction between hydrogen and the oxygenated hydrocarbon to remove
one or more of the oxygen atoms from the oxygenated hydrocarbon to
produce alcohols, ketones, aldehydes, cyclic ethers, esters,
carboxylic acids, hydroxy carboxylic acids, diols and triols. In
general, the heterogeneous deoxygenation catalyst will have both an
active metal function and an acidic function to achieve the
foregoing. For example, acidic supports (e.g., supports having low
isoelectric points) first catalyze dehydration reactions of
oxygenated compounds. Hydrogenation reactions then occur on the
metallic catalyst in the presence of H.sub.2, producing carbon
atoms that are not bonded to oxygen atoms. The bi-functional
dehydration/hydrogenation pathway consumes H.sub.2 and leads to the
subsequent formation of various polyols, diols, ketones, aldehydes,
alcohols, carboxylic acids, hydroxy carboxylic acids and cyclic
ethers, such as furans and pyrans.
The active materials may include, without limitation, Cu, Re, Fe,
Ru, Ir, Co, Rh, Pt, Pd, Ni, W, Os, Mo, Ag, Au, alloys thereof, and
combinations thereof, adhered to a support. The deoxygenation
catalyst may include these elements alone or in combination with
one or more Mn, Cr, Mo, W, V, Nb, Ta, Ti, Zr, Y, La, Sc, Zn, Cd,
Ag, Au, Sn, Ge, P, Al, Ga, In, Tl, Ce, and combinations thereof. In
one embodiment, the deoxygenation catalyst includes Pt, Pd, Ru, Re,
Ni, W or Mo. In yet another embodiment, the deoxygenation catalyst
includes Sn, W, Mo, Ag, Fe and/or Re and at least one transition
metal selected from Ni, Pd, Pt and Ru. In another embodiment, the
catalyst includes Fe, Re and at least Cu or one Group VIIIB
transition metal. In yet another embodiment, the deoxygenation
catalyst includes Pd alloyed or admixed with Cu or Ag and supported
on an acidic support. In yet another embodiment, the deoxygenation
catalyst includes Pd alloyed or admixed with a Group VIB metal
supported on an acidic support. In yet another embodiment, the
deoxygenation catalyst includes Pd alloyed or admixed with a Group
VIB metal and a Group IVA metal on an acidic support. The support
may be any one of a number of supports, including a support having
carbon, silica, alumina, zirconia, titania, tungsten, vanadia,
chromia, zeolites, heteropolyacids, kieselguhr, hydroxyapatite, and
mixtures thereof.
The deoxygenation catalyst may include an acidic support modified
or constructed to provide the desired functionality.
Heteropolyacids are a class of solid-phase acids exemplified by
such species as H.sub.3+xPMo.sub.12-xV.sub.xO.sub.40,
H.sub.4SiW.sub.12O.sub.40, H.sub.3PW.sub.12O.sub.40, and
H.sub.6P2W.sub.18O.sub.62. Heteropolyacids are solid-phase acids
having a well-defined local structure, the most common of which is
the tungsten-based Keggin structure. Other examples may include,
without limitation, tungstated zirconia, tungsten modified
zirconia, tungsten modified alpha-alumina, or tungsten modified
theta alumina.
Loading of the first element (i.e., Cu, Re, Fe, Ru, Ir, Co, Rh, Pt,
Pd, Ni, W, Os, Mo, Ag, Au, alloys and combinations thereof) is in
the range of 0.25 wt % to 25 wt % on carbon, with weight
percentages of 0.10% and 0.05% increments between, such as 1.00%,
1.10%, 1.15%, 2.00%, 2.50%, 5.00%, 10.00%, 12.50%, 15.00% and
20.00%. The preferred atomic ratio of the second element (i.e., Mn,
Cr, Mo, W, V, Nb, Ta, Ti, Zr, Y, La, Sc, Zn, Cd, Ag, Au, Sn, Ge, P,
Al, Ga, In, Tl, Ce, and combinations thereof) is in the range of
0.25-to-1 to 10-to-1, including any ratios between, such as 0.50,
1.00, 2.50, 5.00, and 7.50-to-1. If the catalyst is adhered to a
support, the combination of the catalyst and the support is from
0.25 wt % to 10 wt % of the primary element.
To produce oxygenates, the oxygenated hydrocarbon is combined with
water to provide an aqueous feedstock solution having a
concentration effective for causing the formation of the desired
reaction products. The water-to-carbon ratio on a molar basis is
preferably from about 0.5:1 to about 100:1, including ratios such
as 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 15:1, 25:1,
50:1 75:1, 100:1, and any ratios there-between. The feedstock
solution may also be characterized as a solution having at least
1.0 weight percent (wt %) of the total solution as an oxygenated
hydrocarbon. For instance, the solution may include one or more
oxygenated hydrocarbons, with the total concentration of the
oxygenated hydrocarbons in the solution being at least about 1%,
5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or greater by weight,
including any percentages between, and depending on the oxygenated
hydrocarbons used. In one embodiment, the feedstock solution
includes at least about 10%, 20%, 30%, 40%, 50%, or 60% of a sugar,
such as glucose, fructose, sucrose or xylose, or a sugar alcohol,
such as sorbitol, mannitol, glycerol or xylitol, by weight.
Water-to-carbon ratios and percentages outside of the above stated
ranges are also included. Preferably the balance of the feedstock
solution is water. In some embodiments, the feedstock solution
consists essentially of water, one or more oxygenated hydrocarbons
and, optionally, one or more feedstock modifiers described herein,
such as alkali or hydroxides of alkali or alkali earth salts or
acids. The feedstock solution may also include recycled oxygenated
hydrocarbons recycled from the reactor system. The feedstock
solution may also contain negligible amounts of hydrogen,
preferably less than about 1.5 mole of hydrogen per mole of
feedstock.
The feedstock solution is reacted with hydrogen in the presence of
the deoxygenation catalyst at deoxygenation temperature and
pressure conditions, and weight hourly space velocity, effective to
produce the desired oxygenates. The specific oxygenates produced
will depend on various factors, including the feedstock solution,
reaction temperature, reaction pressure, water concentration,
hydrogen concentration, the reactivity of the catalyst, and the
flow rate of the feedstock solution as it affects the space
velocity (the mass/volume of reactant per unit of catalyst per unit
of time), gas hourly space velocity (GHSV), and weight hourly space
velocity (WHSV). For example, an increase in flow rate, and thereby
a reduction of feedstock exposure to the catalysts over time, will
limit the extent of the reactions which may occur, thereby causing
increased yield for higher level diols and triols, with a reduction
in ketone and alcohol yields.
The deoxygenation temperature and pressure are preferably selected
to maintain at least a portion of the feedstock in the liquid phase
at the reactor inlet. It is recognized, however, that temperature
and pressure conditions may also be selected to more favorably
produce the desired products in the vapor-phase or in a mixed phase
having both a liquid and vapor phase. In general, the reaction
should be conducted at process conditions wherein the
thermodynamics of the proposed reaction are favorable. For
instance, the minimum pressure required to maintain a portion of
the feedstock in the liquid phase will likely vary with the
reaction temperature. As temperatures increase, higher pressures
will generally be required to maintain the feedstock in the liquid
phase, if desired. Pressures above that required to maintain the
feedstock in the liquid phase (i.e., vapor-phase) are also suitable
operating conditions.
In general, the deoxygenation temperature should be greater than
120.degree. C., or 150.degree. C., or 180.degree. C., or
200.degree. C., and less than 325.degree. C., or 300.degree. C., or
280.degree. C., or 260.degree. C., or 240.degree. C., or
220.degree. C. The reaction pressure should be greater than 200
psig, or 365 psig, or 500 psig or 600 psig, and less than 2500
psig, or 2250 psig, or 2000 psig, or 1800 psig, or 1500 psig, or
1200 psig, or 1000 psig. In one embodiment, the deoxygenation
temperature is between about 150.degree. C. and 300.degree. C., or
between about 200.degree. C. and 280.degree. C., or between about
220.degree. C. and 260.degree. C., or between about 150.degree. C.
and 260.degree. C. In another embodiment, the deoxygenation
pressure is between about 365 and 2500 psig, or between about 500
and 2000 psig, or between about 600 and 1800 psig, or between about
365 and 1500 psig.
A condensed liquid phase method may also be performed using a
modifier that increases the activity and/or stability of the
catalyst system. It is preferred that the water and the oxygenated
hydrocarbon are reacted at a suitable pH of from about 1.0 to about
10.0, including pH values in increments of 0.1 and 0.05 between,
and more preferably at a pH of from about 4.0 to about 10.0.
Generally, the modifier is added to the feedstock solution in an
amount ranging from about 0.1% to about 10% by weight as compared
to the total weight of the catalyst system used, although amounts
outside this range are included within the present invention.
In general, the reaction should be conducted under conditions where
the residence time of the feedstock solution over the catalyst is
appropriate to generate the desired products. For example, the WHSV
for the reaction may be at least about 0.1 gram of oxygenated
hydrocarbon per gram of catalyst per hour, and more preferably the
WHSV is about 0.1 to 40.0 g/g hr, including a WHSV of about 0.25,
0.5, 0.75, 1.0, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9,
2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2,
3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5,
4.6, 4.7, 4.8, 4.9, 5.0, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20,
25, 30, 35, 40 g/g hr, and ratios between (including 0.83, 0.85,
0.85, 1.71, 1.72, 1.73, etc.).
The hydrogen used in the deoxygenation reaction may be
in-situ-generated H.sub.2, external H.sub.2 or recycled H.sub.2.
The amount (moles) of external H.sub.2 or recycled H.sub.2
introduced to the feedstock is between 0-100%, 0-95%, 0-90%, 0-85%,
0-80%, 0-75%, 0-70%, 0-65%, 0-60%, 0-55%, 0-50%, 0-45%, 0-40%,
0-35%, 0-30%, 0-25%, 0-20%, 0-15%, 0-10%, 0-5%, 0-2%, or 0-1% of
the total number of moles of the oxygenated hydrocarbon(s) in the
feedstock, including all intervals between. When the feedstock
solution, or any portion thereof, is reacted with APR hydrogen and
external H.sub.2 or recycled H.sub.2, the molar ratio of APR
hydrogen to external H.sub.2 (or recycled H.sub.2) is at least
1:100, 1:50, 1:20; 1:15, 1:10, 1:5; 1:3, 1:2, 1:1, 2:1, 3:1, 5:1,
10:1, 15:1, 20:1, 50:1, 100:1 and ratios between (including 4:1,
6:1, 7:1, 8:1, 9:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1
and 19:1, and vice-versa).
In-Situ Hydrogen Production
One advantage of the present invention is that it allows for the
production and use of in-situ-generated H.sub.2. The APR H.sub.2 is
produced from the feedstock under aqueous phase reforming
conditions using an aqueous phase reforming catalyst (APR
catalyst). The APR catalyst is preferably a heterogeneous catalyst
capable of catalyzing the reaction of water and oxygenated
hydrocarbons to form H.sub.2 under the conditions described below.
In one embodiment, the APR catalyst includes a support and at least
one Group VIIIB metal, Fe, Ru, Ir, Co, Rh, Pt, Pd, Ni, alloys and
combinations thereof. The APR catalyst may also include at least
one additional material from Group VIIIB, Group VIIB, Group VIB,
Group VB, Group IVB, Group IIB, Group IB, Group IVA or Group VA
metals, such as Cu, B, Mn, Re, Cr, Mo, Bi, W, V, Nb, Ta, Ti, Zr, Y,
La, Sc, Zn, Cd, Ag, Au, Sn, Ge, P, Al, Ga, In, Tl, Ce, alloys and
combinations thereof. The preferred Group VIIB metal includes Re,
Mn, or combinations thereof. The preferred Group VIB metal includes
Cr, Mo, W, or a combination thereof. The preferred Group VIIIB
metals include Pt, Rh, Ru, Pd, Ni, or combinations thereof. The
supports may include any one of the catalyst supports described
below, depending on the desired activity of the catalyst
system.
The APR catalyst may also be atomically identical to the
deoxygenation catalyst. For instance, the APR and deoxygenation
catalyst may include Pt alloyed or admixed with Ni, Ru, Cu, Fe, Rh,
Re, alloys and combinations thereof. The APR catalyst and
deoxygenation catalyst may also include Ru alloyed or admixed with
Ge, Bi, B, Ni, Sn, Cu, Fe, Rh, Pt, alloys and combinations thereof.
The APR catalyst may also include Ni alloyed or admixed with Sn,
Ge, Bi, B, Cu, Re, Ru, Fe, alloys and combinations thereof.
Preferred loading of the primary Group VIIIB metal is in the range
of 0.25 wt % to 25 wt % on carbon, with weight percentages of 0.10%
and 0.05% increments between, such as 1.00%, 1.10%, 1.15%, 2.00%,
2.50%, 5.00%, 10.00%, 12.50%, 15.00% and 20.00%. The preferred
atomic ratio of the second material is in the range of 0.25-to-1 to
10-to-1, including ratios between, such as 0.50, 1.00, 2.50, 5.00,
and 7.50-to-1.
A preferred catalyst composition is further achieved by the
addition of oxides of Group IIIB, and associated rare earth oxides.
In such event, the preferred components would be oxides of either
lanthanum or cerium. The preferred atomic ratio of the Group IIIB
compounds to the primary Group VIIIB metal is in the range of
0.25-to-1 to 10-to-1, including ratios between, such as 0.50, 1.00,
2.50, 5.00, and 7.50-to-1.
Another preferred catalyst composition is one containing platinum
and rhenium. The preferred atomic ratio of Pt to Re is in the range
of 0.25-to-1 to 10-to-1, including ratios there-between, such as
0.50, 1.00, 2.50, 5.00, and 7.00-to-1. The preferred loading of the
Pt is in the range of 0.25 wt % to 5.0 wt %, with weight
percentages of 0.10% and 0.05% between, such as 0.35%, 0.45%,
0.75%, 1.10%, 1.15%, 2.00%, 2.50%, 3.0%, and 4.0%.
Preferably, the APR catalyst and the deoxygenation catalyst are of
the same atomic formulation. The catalysts may also be of different
formulations. The catalysts may also be a single catalyst with both
APR and deoxygenation functionality provided by the combination of
the above described APR materials and deoxygenation materials. In
such event, the preferred atomic ratio of the APR catalyst to the
deoxygenation catalyst is in the range of 5:1 to 1:5, such as,
without limitation, 4.5:1, 4.0:1, 3.5:1, 3.0:1, 2.5:1, 2.0:1,
1.5:1, 1:1, 1:1.5, 1:2.0, 1:2.5, 1:3.0, 1:3.5, 1:4.0, 1:4.5, and
any amounts between.
Similar to the deoxygenation reactions, the temperature and
pressure conditions are preferably selected to maintain at least a
portion of the feedstock in the liquid phase at the reactor inlet.
The reforming temperature and pressure conditions may also be
selected to more favorably produce the desired products in the
vapor-phase or in a mixed phase having both a liquid and vapor
phase. In general, the APR reaction should be conducted at a
temperature where the thermodynamics are favorable. For instance,
the minimum pressure required to maintain a portion of the
feedstock in the liquid phase will vary with the reaction
temperature. As temperatures increase, higher pressures will
generally be required to maintain the feedstock in the liquid
phase. Any pressure above that required to maintain the feedstock
in the liquid phase (i.e., vapor-phase) is also a suitable
operating pressure. For vapor phase reactions, the reaction should
be conducted at a reforming temperature where the vapor pressure of
the oxygenated hydrocarbon compound is at least about 0.1 atm (and
preferably a good deal higher), and the thermodynamics of the
reaction are favorable. The temperature will vary depending upon
the specific oxygenated hydrocarbon compound used, but is generally
in the range of from about 100.degree. C. to 450.degree. C., or
from about 100.degree. C. to 300.degree. C., for reactions taking
place in the vapor phase. For liquid phase reactions, the reaction
temperature may be from about 80.degree. C. to 400.degree. C., and
the reaction pressure from about 72 psig to 1300 psig.
In one embodiment, the reaction temperature is between about
100.degree. C. and 400.degree. C., or between about 120.degree. C.
and 300.degree. C., or between about 200.degree. C. and 280.degree.
C., or between about 150.degree. C. and 270.degree. C. The reaction
pressure is preferably between about 72 and 1300 psig, or between
about 72 and 1200 psig, or between about 145 and 1200 psig, or
between about 200 and 725 psig, or between about 365 and 700 psig,
or between about 600 and 650 psig.
In embodiments where the APR catalyst and the deoxygenation
catalyst are combined into a single catalyst, or the reactions are
conducted simultaneously in a single reactor, the reforming
temperature and deoxygenation temperature may be in the range of
about 100.degree. C. to 325.degree. C., or about 120.degree. C. to
300.degree. C., or about 200.degree. C. to 280.degree. C., and the
reforming pressure and deoxygenation pressure may be in the range
of about 200 psig to 1500 psig, or about 200 psig to 1200 psig, or
about 200 psig to 725 psig.
A condensed liquid phase method may also be performed using a
modifier that increases the activity and/or stability of the APR
catalyst system. It is preferred that the water and the oxygenated
hydrocarbon are reacted at a suitable pH of from about 1.0 to 10.0,
or at a pH of from about 4.0 to 10.0, including pH value increments
of 0.1 and 0.05 between. Generally, the modifier is added to the
feedstock solution in an amount ranging from about 0.1% to about
10% by weight as compared to the total weight of the catalyst
system used, although amounts outside this range are included
within the present invention.
Alkali or alkali earth salts may also be added to the feedstock
solution to optimize the proportion of hydrogen in the reaction
products. Examples of suitable water-soluble salts include one or
more selected from the group consisting of an alkali or an alkali
earth metal hydroxide, carbonate, nitrate, or chloride salt. For
example, adding alkali (basic) salts to provide a pH of about pH
4.0 to about pH 10.0 can improve hydrogen selectivity of reforming
reactions.
The addition of acidic compounds may also provide increased
selectivity to the desired reaction products in the hydrogenation
reactions described below. It is preferred that the water-soluble
acid is selected from the group consisting of nitrate, phosphate,
sulfate, chloride salts, and mixtures thereof. If an acidic
modifier is used, it is preferred that it be present in an amount
sufficient to lower the pH of the aqueous feed stream to a value
between about pH 1.0 and about pH 4.0. Lowering the pH of a feed
stream in this manner may increase the proportion of oxygenates in
the final reaction products.
In general, the reaction should be conducted under conditions where
the residence time of the feedstock solution over the APR catalyst
is appropriate to generate an amount of APR hydrogen sufficient to
react with a second portion of the feedstock solution over the
deoxygenation catalyst to provide the desired oxygenates. For
example, the WHSV for the reaction may be at least about 0.1 gram
of oxygenated hydrocarbon per gram of APR catalyst, and preferably
between about 1.0 to 40.0 grams of oxygenated hydrocarbon per gram
of APR catalyst, and more preferably between about 0.5 to 8.0 grams
of oxygenated hydrocarbon per gram of APR catalyst. In terms of
scaled-up production, after start-up, the APR reactor system should
be process controlled so that the reactions proceed at steady-state
equilibrium.
Biomass Processing Solvent with C.sub.4+ Compounds
The biomass processing solvent or solvent mixture may also include
C.sub.4+ compounds derived from the further processing of the
oxygenates. In such applications, oxygenates are further converted
into C.sub.4+ compounds by condensation in the presence of a
condensation catalyst. The condensation catalyst will generally be
a catalyst capable of forming longer chain compounds by linking two
oxygen containing species through a new carbon-carbon bond, and
converting the resulting compound to a hydrocarbon, alcohol or
ketone, such as an acid catalyst, basic catalyst or a
multi-functional catalyst having both acid and base functionality.
The condensation catalyst may include, without limitation,
carbides, nitrides, zirconia, alumina, silica, aluminosilicates,
phosphates, zeolites, titanium oxides, zinc oxides, vanadium
oxides, lanthanum oxides, yttrium oxides, scandium oxides,
magnesium oxides, cerium oxides, barium oxides, calcium oxides,
hydroxides, heteropolyacids, inorganic acids, acid modified resins,
base modified resins, and combinations thereof. The condensation
catalyst may include the above alone or in combination with a
modifier, such as Ce, La, Y, Sc, P, B, Bi, Li, Na, K, Rb, Cs, Mg,
Ca, Sr, Ba, and combinations thereof. The condensation catalyst may
also include a metal, such as Cu, Ag, Au, Pt, Ni, Fe, Co, Ru, Zn,
Cd, Ga, In, Rh, Pd, Ir, Re, Mn, Cr, Mo, W, Sn, Os, alloys and
combinations thereof, to provide a metal functionality. The
condensation catalyst may also be atomically identical to the APR
catalyst and/or the deoxygenation catalyst, or combined in a single
catalytic form to provide the APR and/or deoxygenation and/or
condensation functionality.
The condensation catalyst may be self-supporting (i.e., the
catalyst does not need another material to serve as a support), or
may require a separate support suitable for suspending the catalyst
in the reactant stream. One particularly beneficial support is
silica, especially silica having a high surface area (greater than
100 square meters per gram), obtained by sol-gel synthesis,
precipitation or fuming. In other embodiments, particularly when
the condensation catalyst is a powder, the catalyst system may
include a binder to assist in forming the catalyst into a desirable
catalyst shape. Applicable forming processes include extrusion,
pelletization, oil dropping, or other known processes. Zinc oxide,
alumina, and a peptizing agent may also be mixed together and
extruded to produce a formed material. After drying, this material
is calcined at a temperature appropriate for formation of the
catalytically active phase, which usually requires temperatures in
excess of 450.degree. C.
In certain applications, the condensation reaction is performed
using acidic catalysts. The acid catalysts may include, without
limitation, aluminosilicates (zeolites), silica-alumina phosphates
(SAPO), aluminum phosphates (ALPO), amorphous silica alumina,
zirconia, sulfated zirconia, tungstated zirconia, tungsten carbide,
molybdenum carbide, titania, acidic alumina, phosphated alumina,
phosphated silica, sulfated carbons, phosphated carbons, acidic
resins, heteropolyacids, inorganic acids, and combinations thereof.
In one embodiment, the catalyst may also include a modifier, such
as Ce, Y, Sc, La, P, B, Bi, Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, and
combinations thereof. The catalyst may also be modified by the
addition of a metal, such as Cu, Ag, Au, Pt, Ni, Fe, Co, Ru, Zn,
Cd, Ga, In, Rh, Pd, Ir, Re, Mn, Cr, Mo, W, Sn, Os, alloys and
combinations thereof, to provide metal functionality, and/or
sulfides and oxide of Ti, Zr, V, Nb, Ta, Mo, Cr, W, Mn, Re, Al, Ga,
In, Fe, Co, Ir, Ni, Si, Cu, Zn, Sn, Cd, P, and combinations
thereof. Gallium has also been found to be particularly useful as a
promoter for the present process. The acid catalyst may be
homogenous, self-supporting or adhered to any one of the supports
further described below, including supports containing carbon,
silica, alumina, zirconia, titania, vanadia, ceria, nitride, boron
nitride, heteropolyacids, alloys and mixtures thereof.
Ga, In, Zn, Fe, Mo, Ag, Au, Ni, P, Sc, Y, Ta, and lanthanides may
also be exchanged onto zeolites to provide a zeolite catalyst
having activity. The term "zeolite" as used herein refers not only
to microporous crystalline aluminosilicate but also for microporous
crystalline metal-containing aluminosilicate structures, such as
galloaluminosilicates and gallosilicates. Metal functionality may
be provided by metals such as Cu, Ag, Au, Pt, Ni, Fe, Co, Ru, Zn,
Cd, Ga, In, Rh, Pd, Ir, Re, Mn, Cr, Mo, W, Sn, Os, alloys and
combinations thereof.
Examples of suitable zeolite catalysts include ZSM-5, ZSM-11,
ZSM-12, ZSM-22, ZSM-23, ZSM-35 and ZSM-48. Zeolite ZSM-5, and the
conventional preparation thereof, is described in U.S. Pat. No.
3,702,886; Re. 29,948 (highly siliceous ZSM-5); U.S. Pat. No.
4,100,262 and U.S. Pat. No. 4,139,600, all incorporated herein by
reference. Zeolite ZSM-11, and the conventional preparation
thereof, is described in U.S. Pat. No. 3,709,979, which is also
incorporated herein by reference. Zeolite ZSM-12, and the
conventional preparation thereof, is described in U.S. Pat. No.
3,832,449, incorporated herein by reference. Zeolite ZSM-23, and
the conventional preparation thereof, is described in U.S. Pat. No.
4,076,842, incorporated herein by reference. Zeolite ZSM-35, and
the conventional preparation thereof, is described in U.S. Pat. No.
4,016,245, incorporated herein by reference. Another preparation of
ZSM-35 is described in U.S. Pat. No. 4,107,195, the disclosure of
which is incorporated herein by reference. ZSM-48, and the
conventional preparation thereof, is taught by U.S. Pat. No.
4,375,573, incorporated herein by reference. Other examples of
zeolite catalysts are described in U.S. Pat. No. 5,019,663 and U.S.
Pat. No. 7,022,888, also incorporated herein by reference.
As described in U.S. Pat. No. 7,022,888, the acid catalyst may be a
bifunctional pentasil zeolite catalyst including at least one
metallic element from the group of Cu, Ag, Au, Pt, Ni, Fe, Co, Ru,
Zn, Cd, Ga, In, Rh, Pd, Ir, Re, Mn, Cr, Mo, W, Sn, Os, alloys and
combinations thereof, or a modifier from the group of Ga, In, Zn,
Fe, Mo, Au, Ag, Y, Sc, Ni, P, Ta, lanthanides, and combinations
thereof. The zeolite preferably has a strong acidic and
dehydrogenation sites, and may be used with reactant streams
containing and an oxygenated hydrocarbon at a temperature of below
500.degree. C. The bifunctional pentasil zeolite may have ZSM-5,
ZSM-8 or ZSM-11 type crystal structure consisting of a large number
of 5-membered oxygen-rings, i.e., pentasil rings. The zeolite with
ZSM-5 type structure is a particularly preferred catalyst. The
bifunctional pentasil zeolite catalyst is preferably Ga and/or
In-modified ZSM-5 type zeolites such as Ga and/or In-impregnated
H-ZSM-5, Ga and/or In-exchanged H-ZSM-5, H-gallosilicate of ZSM-5
type structure and H-galloaluminosilicate of ZSM-5 type structure.
The bifunctional ZSM-5 type pentasil zeolite may contain
tetrahedral aluminum and/or gallium present in the zeolite
framework or lattice and octahedral gallium or indium. The
octahedral sites are preferably not present in the zeolite
framework but are present in the zeolite channels in a close
vicinity of the zeolitic protonic acid sites, which are attributed
to the presence of tetrahedral aluminum and gallium in the zeolite.
The tetrahedral or framework Al and/or Ga is believed to be
responsible for the acid function of zeolite and octahedral or
non-framework Ga and/or In is believed to be responsible for the
dehydrogenation function of the zeolite.
In one embodiment, the condensation catalyst may be a
H-galloaluminosilicate of ZSM-5 type bifunctional pentasil zeolite
having framework (tetrahedral) Si/Al and Si/Ga mole ratio of about
10-100 and 15-150, respectively, and non-framework (octahedral) Ga
of about 0.5-5.0 wt. %. When these pentasil H-galloaluminosilicate
zeolites are used as a condensation catalyst, the density of strong
acid sites can be controlled by the framework Al/Si mole ratio: the
higher the Al/Si ratio, the higher the density of strong acid
sites. The highly dispersed non-framework gallium oxide species can
be obtained by the degalliation of the zeolite by its pre-treatment
with H.sub.2 and steam. The zeolite containing strong acid sites
with high density and also highly dispersed non-framework gallium
oxide species in close proximity of the zeolite acid site is
preferred. The catalyst may optionally contain any binder such as
alumina, silica or clay material. The catalyst can be used in the
form of pellets, extrudates and particles of different shapes and
sizes.
The acidic catalysts may include one or more zeolite structures
comprising cage-like structures of silica-alumina. Zeolites are
crystalline microporous materials with well-defined pore structure.
Zeolites contain active sites, usually acid sites, which can be
generated in the zeolite framework. The strength and concentration
of the active sites can be tailored for particular applications.
Examples of suitable zeolites for condensing secondary alcohols and
alkanes may comprise aluminosilicates optionally modified with
cations, such as Ga, In, Zn, Mo, and mixtures of such cations, as
described, for example, in U.S. Pat. No. 3,702,886, which is
incorporated herein by reference. As recognized in the art, the
structure of the particular zeolite or zeolites may be altered to
provide different amounts of various hydrocarbon species in the
product mixture. Depending on the structure of the zeolite
catalyst, the product mixture may contain various amounts of
aromatic and cyclic hydrocarbons.
Alternatively, solid acid catalysts such as alumina modified with
phosphates, chloride, silica, and other acidic oxides could be used
in practicing the present invention. Also, either sulfated zirconia
or tungstated zirconia may provide the necessary acidity. Re and
Pt/Re catalysts are also useful for promoting condensation of
oxygenates to C.sub.5+ hydrocarbons and/or C.sub.5+
mono-oxygenates. The Re is sufficiently acidic to promote
acid-catalyzed condensation. Acidity may also be added to activated
carbon by the addition of either sulfates or phosphates.
The condensation reactions result in the production of C.sub.4+
alkanes, C.sub.4+ alkenes, C.sub.5+ cycloalkanes, C.sub.5+
cycloalkenes, aryls, fused aryls, C.sub.4+ alcohols, C.sub.4+
ketones, and mixtures thereof. The C.sub.4+ alkanes and C.sub.4+
alkenes have from 4 to 30 carbon atoms (C.sub.4-30 alkanes and
C.sub.4-30 alkenes) and may be branched or straight chained alkanes
or alkenes. The C.sub.4+ alkanes and C.sub.4+ alkenes may also
include fractions of C.sub.4-9, C.sub.7-14, C.sub.12-24 alkanes and
alkenes, respectively, with the C.sub.4-9 fraction directed to
gasoline, the C.sub.7-14 fraction directed to jet fuels, and the
C.sub.12-24 fraction directed to diesel fuel and other industrial
applications. Examples of various C.sub.4+ alkanes and C.sub.4+
alkenes include, without limitation, butane, butane, pentane,
pentene, 2-methylbutane, hexane, hexane, 2-methylpentane,
3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, heptane,
heptene, octane, octene, 2,2,4,-trimethylpentane, 2,3-dimethyl
hexane, 2,3,4-trimethylpentane, 2,3-dimethylpentane, nonane,
nonene, decane, decene, undecane, undecene, dodecane, dodecene,
tridecane, tridecene, tetradecane, tetradecene, pentadecane,
pentadecene, hexadecane, hexadecane, heptyldecane, heptyldecene,
octyldecane, octyldecene, nonyldecane, nonyldecene, eicosane,
eicosene, uneicosane, uneicosene, doeicosane, doeicosene,
trieicosane, trieicosene, tetraeicosane, tetraeicosene, and isomers
thereof.
The C.sub.5+ cycloalkanes and C.sub.5+ cycloalkenes have from 5 to
30 carbon atoms and may be unsubstituted, mono-substituted or
multi-substituted. In the case of mono-substituted and
multi-substituted compounds, the substituted group may include a
branched C.sub.3+ alkyl, a straight chain C.sub.1+ alkyl, a
branched C.sub.3+ alkylene, a straight chain C.sub.1+ alkylene, a
straight chain C.sub.2+ alkylene, a phenyl or a combination
thereof. In one embodiment, at least one of the substituted groups
include a branched C.sub.3-12 alkyl, a straight chain C.sub.1-12
alkyl, a branched C.sub.3-12 alkylene, a straight chain C.sub.1-12
alkylene, a straight chain C.sub.2-12 alkylene, a phenyl or a
combination thereof. In yet another embodiment, at least one of the
substituted groups include a branched C.sub.3-4 alkyl, a straight
chain C.sub.1-4 alkyl, a branched C.sub.3-4 alkylene, straight
chain C.sub.1-4 alkylene, straight chain C.sub.2-4 alkylene, a
phenyl or a combination thereof. Examples of desirable C.sub.5+
cycloalkanes and C.sub.5+ cycloalkenes include, without limitation,
cyclopentane, cyclopentene, cyclohexane, cyclohexene,
methyl-cyclopentane, methyl-cyclopentene, ethyl-cyclopentane,
ethyl-cyclopentene, ethyl-cyclohexane, ethyl-cyclohexene, and
isomers thereof.
Biomass Deconstruction
In the deconstruction process, the biomass slurry is combined with
the biomass processing solvent described above and reacted to form
a biomass hydrolysate. Preferably the biomass slurry comprises
10-50% of the feedstock. The biomass slurry may include any type of
biomass, including but not limited to chopped or ground solids,
microcrystalline or cotton cellulose, wood or non-wood
lignocelluloses, recycle fibers such as newspaper and paperboard,
forest and agricultural waste residues, including sawdust, bagasse,
and corn stover, and energy crops, such as miscanthus, switch
grass, sorghum and others. The biomass processing solvent contains
a wide range of oxygenates as described above.
The deconstruction process can be either batch or continuous. In
one embodiment, the deconstruction is a continuous process using
one or more continuous stirred-tank reactors in parallel or in
series. The deconstruction temperature will generally be greater
than 80.degree. C., or 120.degree. C., or 150.degree. C., or
180.degree. C., or 250.degree. C., and less than 350.degree. C., or
325.degree. C., or 300.degree. C., or 260.degree. C. In one
embodiment, the deconstruction temperature is between about
80.degree. C. and 350.degree. C., or between about 120.degree. C.
and 300.degree. C., or between about 150.degree. C. and 260.degree.
C., or between about 180.degree. C. and 260.degree. C.
The deconstruction pressure is generally greater than 100 psi, or
250 psi, or 300 psi, or 625 psi, or 900 psi, or 1000 psi, or 1200
psi, and less than 2000 psi, or 1500 psi, or 1200 psi. In one
embodiment, the deconstruction temperature is between about 300 psi
and 2000 psi, or between about 300 psi and 1500 psi, or between
about 1000 psi and 1500 psi. Preferably, the slurry contacts the
solvent for between approximately 5 minutes and 2 hours.
The deconstruction process fractionates and solubilizes a portion
of the cellulose, lignin and hemicellulose originating in the
biomass. Through this process, lignin, cellulose and hemicellulose
decompose to carbohydrates, starches, monosaccharides,
disaccharides, polysaccharides, sugars, sugar alcohols, alditols,
polyols and mixtures thereof. Unreacted components can be separated
through phase separation with minimal cross contamination.
Exemplary biomass deconstruction products include unreacted or
under-reacted biomass (e.g., residual biomass), ash components,
extractives, organic products, lignin and lignocellulosic
derivatives, cellulose and cellulosic derivatives, hemicellulose
and hemicellulosic derivatives, carbohydrates, starches,
monosaccharides, disaccharides, polysaccharides, sugars, sugar
alcohols, alditols, polyols, phenols, and mixtures thereof.
Compounds derived from lignin, cellulose and hemicellulose include
propanal, 1-propanol, 2-butanone, 1-butanol, 2,3-pentanedione,
2,5-dimethyl-furan, 1-pentanol, cyclopentanone,
2-methyl-cyclopentanone, 2-ethyl-cyclopentanone,
2-propylcyclopentanone, phenol, 4-methyl-phenol, 2-methoxy-phenol,
4-ethyl-phenol, 4-ethyl-2-methoxy-phenol, 4-propyl-phenol,
4-ethyl-2-methoxy-phenol, 2,6-dimethoxy-phenol,
2-methoxy-4-propyl-phenol, 2-methoxy-3-(2-propenyl)-phenol,
1-(2,5-dimethoxyphenyl)-propanol,
2,6-dimethoxy-4-(2-propenyl)-phenol, acetone,
2-methyl-tetrahydrofuran, 2,5-dimethyl-tetrahydrofuran,
tetrahydro-2-methyl-2H-pyran, 3-hexanone, 2-hexanone, hexanal,
tetrahydro-2-methanol-2H-pyran, and isomers thereof. Extractives
include terpenoids, stilbenes, flavonoids, phenolics, aliphatics,
lignans, alkanes, proteinaceous materials, etc. Ash components
include Al, Ba, Ca, Fe, K, Mg, Mn, P, S, Si, Zn, etc.
Dewatering of the Biomass Hydrolysate
The biomass hydrolysate product stream contains large amounts of
water, which may impact reactor size, catalyst activity and overall
cost-effectiveness of the process. As a result, dewatering the
biomass hydrolysate may create more favorable conditions for
downstream bioreforming process reactions. Suitable dewatering
processes are known in the art and include wet classification,
centrifugation, filtration, or similar solid-liquid separation
processes.
Recycling of Biomass Processing Solvent
As shown above, the bioreforming process produces a complex mixture
of organic compounds. In one embodiment, after completing a
bioreforming process such as APR and/or HDO, various process
streams can be separated and recycled for use as the biomass
processing solvent or directed to further processing for conversion
to liquid fuels and chemicals.
In one embodiment, the products from the APR/HDO processes can be
separated based on the thermodynamic properties (e.g., boiling
point) of the oxygenates using standard fractionation techniques.
In such application, the more volatile compounds are separated from
a bottom stream containing heavier and less volatile compounds.
This heavy bottom stream includes some of the components listed in
Table 1 above. The heavy bottom stream can be divided such that
some of the heavy bottom stream is recycled into the bioreforming
process to undergo further processing, with the remainder of the
heavy bottom stream recycled to mix with the biomass slurry prior
to the deconstruction process. The organic compounds in the heavy
bottom stream help dissolve and crack lignin, which improves lignin
removal from the biomass slurry.
In another embodiment of the present invention, an effluent stream
can be separated from the bioreforming product stream. This
effluent stream includes the organic phase components listed in
Table 1, as well as some of the aqueous phase components listed in
Table 1. The effluent stream can be recycled to mix with the
biomass slurry prior to the deconstruction process. The residual
organic acids in the effluent stream can improve biomass
deconstruction.
In certain embodiments, the biomass deconstruction and the
bioreforming process may be conducted simultaneously in a single
reactor. An example of such a reactor is a slurry reactor wherein
the biomass is introduced in a first end with a recycle stream that
includes both unreacted or under-reacted biomass and biomass
processing solvent collected from a later heavy bottom stream. In
such applications, the biomass processing solvent promotes biomass
deconstruction, which in turn provides oxygenated hydrocarbons for
conversion into oxygenates by the deoxygenation catalyst in the
reactor. A portion of the oxygenates, in turn, may be either
maintained in the reactor, recycled for use as a biomass processing
solvent and/or further processed to provide liquid fuels and
chemicals.
The biomass deconstruction process described herein efficiently
utilizes the available components in lignocellulosic biomass by
hydrolyzing the lignin, cellulose and hemicellulose to provide
water-soluble oxygenated hydrocarbons for further use in
bioreforming processes. The biomass deconstruction process reduces
biomass deconstruction costs by avoiding the need to purchase
expensive deconstruction solvents and by avoiding solvent recovery
and clean-up costs by recycling solvent from intermediates produced
in bioreforming processes. The biomass deconstruction process also
provides a bioreforming stream by solubilizing lignin, cellulose
and hemicellulose components into useable carbohydrates, starches,
monosaccharides, disaccharides, polysaccharides, sugars, sugar
alcohols, alditols, polyols and mixtures thereof.
Example 1
A preliminary deconstruction trial was conducted using a mixture of
bioreforming organic phase products. The solvent was composed of 60
wt % bioreforming organic phase materials and 40 wt % deionized
water. A biomass slurry having a biomass concentration of 5 wt %
sugarcane bagasse in solvent was reacted over a period of two hours
at a temperature of 180.degree. C. in an autoclave reactor. The
reaction resulted in 40% conversion of the sugarcane bagasse to
organic and aqueous phase products, with low lignin content fibers
as residual solids. The visible delignification effects indicated
that the complex organic mixture from the bioreforming process
contains compounds useful as a highly efficient deconstruction
solvent.
Example 2
Experimental results of initial biomass deconstruction using
benzene, toluene, and 4-methyl-2-pentanone are shown in FIG. 3.
Reaction conditions were 10% bagasse, 170.degree. C., 500 psi N2,
30 min heating, 30 min retention. Solvent was mixed with water to
give the target weight percent as depicted in FIG. 3. With the high
concentration solvent, some of the lignin was deconstructed,
producing liquid form products.
Example 3
A deconstruction trial was conducted using APR aqueous products,
the major compounds of which are shown in FIG. 4, as a solvent to
liquefy lignin residue derived from a separated enzymatic
hydrolysate of corn stover. 10.0 g of lignin was loaded in a batch
reactor with 100 g of APR aqueous products. The reactor was sealed
and pressurized to 101.6 psi (at room temperature) with nitrogen
and stirred at 800 RPM. The slurry was heated to 190.degree. C. (at
pressure of 330 psi) and soaked for 90 minutes. Lignin was 100%
liquefied at the end of experiment producing liquid phase biomass
hydrolysate, indicating that the APR aqueous products contains
compounds useful as a highly efficient deconstruction solvent.
Example 4
A deconstruction trial was conducted using a deoxygenation catalyst
consisting of 2% Pd, 2% Ru, and 13.5% W on m-ZrO.sub.2. The reactor
was loaded with 40 grams of catalyst along with a feed of 120 grams
of corn stover and 12,000 grams of water. The reactor system was
operated with an initial temperature ramp to 285.degree. C. at
2.4.degree. C./min and consisted of a profile between 240 and
285.degree. C. for the remainder of the trial. The reactor pressure
was controlled between 1000 and 1150 psi with continuous hydrogen
sparging of 2.1 mol H.sub.2/hr.
Greater than 80% of the corn stover was converted to a three-phase
(residual solid phase, aqueous phase, and organic/wax phase)
slurry. The residual solids were separated to recover the catalyst
for regeneration. The product profile of the aqueous phase is
illustrated in FIG. 5. A portion of the aqueous phase can be
separated and used as a processing solvent for the deconstruction
of biomass. The organic phase has a significant amount of biomass
extractives including compounds like vitamin E, steroids,
stilbenoids, terpenes, long-chain fatty acids, long-chain
hydrocarbons, etc., as well as substituted benzenes.
Analysis of the organic phase included pyrolysis in combination
with gas chromatography (GC) and mass spectrometry (MS) (Japan
analytical Industry Model JCI-22 connected to a Thermo-Electron
Trace GC Ultra with DSQII MS). The analytical results are shown in
FIGS. 6, 7, and 8.
* * * * *